In various technical fields using networks of relatively numerous wires, cables or conduits, the practical problem arises of being able, by knowing the position of one end of a wire, cable or conduit, to identify the position of the other end of the same wire, cable or conduit in a precise and certain manner. Such is the case, in particular, with leads called computer “jumper” leads, housed in a cabinet or a case, telephone “patching” systems, or wires and cables of electrical cable assemblies, whether these be wires conveying data signals, or power cables, etc.
More particularly in the case of cabinets referred to as “jumper” cabinets for computer links, many “jumper” leads are passed between the active computer hardware and the jumper panels, and it is very difficult to follow a lead over its entire length, from one of its ends, in order to be able to find its other end and thus make the link between a connector of given number of the distribution cable assembly and a port number of an active hardware item.
The current possible ways of locating the inputs and outputs of a cable or of a lead are the following:                the simplest and most direct method is “physical” tracking, by sight or touch. However, this first method is not very practical, and a source of errors, in the case of many entangled leads;        another method consists in marking the cables or leads at both their ends, by labeling them. Each cable or lead end is thus identified in theory, but there is an obvious difficulty in rapidly locating an end of a lead already in place (from a multiplicity of leads);        it is also possible to distinguish the cables or leads by different external colors, but this method does not offer sufficient options, the maximum number of colors available being of the order of ten;        another method may consist in disconnecting the cables or leads, in order to identify them according to the consequence of their disconnection, but this means a temporary stoppage of the operation of the system connected to the cable or lead that has been disconnected, which stoppage is in many cases unacceptable;        one technical solution available consists of specific software and a specific database. However, this solution is complex to manage, a source of errors during updating, and very expensive;        it is also possible to use an automatic acquisition system, but the latter solution, involving the addition of an electrical conductor in each cable or lead, is a source of electromagnetic interference when injecting an electrical signal into the additional conductor.        
One exemple disclosed in U.S. Pat. No. 5,666,453 A describes fiber-optic cables or leads provided with a system for locating the ends by means of light-emitting diodes supplied via electrical conductors incorporated into the leads or cables. This solution therefore requires the incorporation of electrical circuits and of specific components, such as light-emitting diodes, on all the leads and cables to be located. Thus, such a solution is particularly expensive, given the large number of cables or leads that have to be equipped therewith. In addition, the electrical conductors of this system may create electromagnetic interference.
Another exemple disclosd in U.S. Pat. No. 5,625,735 A, or its corresponding F.R. Patent No. 2 725 796 A discribes an optical solution applied to fiber-optic leads for determining the orientation of the plane of polarization of the end of the optical fiber for the purpose of connecting it correctly. This document is therefore not aimed at locating or identifying the ends of cables or leads, making it alien to the objectives of the present invention.